You might want to take it easy with that five-blade razor, bros. A new study boldly trumpets that men with scruffy facial hair are considered significantly more attractive than their beard-deficient brethren. At least on the surface, the findings bolster the notion that dudes like Hugh Jackman and Jake Gyllenhaal take their handsome-powers up a notch with a bit of well-kept stubble.

Compared to previous beard-attractiveness studies — which are apparently a thing — this research zeroed in on the precise amount of scruff that straight women and straight men find most desirable. The magic daily number for growing out your whiskers, sexily? A whole 10 days.

The latest manly-man findings come courtesy of researchers Barnaby J. Dixson and Robert C. Brooks of the Evolution & Ecology Research Centre at the University of New South Wales. Their methodology was fairly straightforward: They showed 350 straight women and 250 straight men pictures of the same guy with varying degrees of facial hair, like so:

Facial hair "strongly influences people's judgments of men's socio-sexual attributes," they concluded. Those judgments, however, were based on a few different factors beyond evolutionary psychology (emphasis added):

Women judged faces with heavy stubble as most attractive and heavy beards, light stubble and clean-shaven faces as similarly less attractive. In contrast, men rated full beards and heavy stubble as most attractive, followed closely by clean-shaven and light stubble as least attractive. Men and women rated full beards highest for parenting ability and healthiness. Masculinity ratings increased linearly as facial hair increased, and this effect was more pronounced in women in the fertile phase of the menstrual cycle, although attractiveness ratings did not differ according to fertility. [Discover Magazine]

A few caveats. Note that "masculine" in this case doesn't necessarily translate into "attractive." If it did, women would be more partial to the full-on lumberjack, but instead were more inclined to sing the praises of heavy stubble (the aforementioned 10-day scruff).

The findings don't exactly jibe with a 2012 joint study of beard attraction by psychologists from Canada's University of Lethbridge and New Zealand's Victoria University of Wellington. Researchers used similar methodology to discover that while ladies found men with beards "older and more aggressive" (alpha males, in other words), they still preferred the mugs of clean-shaven guys.

That's confusing, I know. But at least the two studies act as bookends for what lovelorn bearded gents can work with. If you're a straight male growing a beard in hopes of attracting a female cabin-mate to sit with in front of the fire, evolutionary science seems to be on your side as long as your facial hair is clean and tidy and within reason. Being Hugh Jackman probably wouldn't hurt your chances, either.